Field of the Invention
Embodiments of the invention relate to a solar cell module.
Description of the Related Art
Recently, as existing energy sources such as petroleum and coal are expected to be depleted, interests in alternative energy sources for replacing the existing energy sources are increasing. Among the alternative energy sources, solar cells for generating electric energy from solar energy have been particularly spotlighted.
A solar cell generally includes semiconductor parts, which respectively have different conductive types, for example, a p-type and an n-type and thus form a p-n junction, and electrodes respectively connected to the semiconductor parts of the different conductive types.
When light is incident on the solar cell, a plurality of electron-hole pairs are produced in the semiconductor parts and are separated into electrons and holes by the incident light. The electrons move to the n-type semiconductor part, and the holes move to the p-type semiconductor part. Then, the electrons and the holes are collected by the different electrodes respectively connected to the n-type semiconductor part and the p-type semiconductor part. The electrodes are connected to each other using electric wires to thereby obtain electric power.
A plurality of solar cells having the above-described configuration may be connected to one another through intercell connectors to form a module.
In a back contact solar cell, in which all of electrodes are connected to a back surface, metal wires may be connected to electrodes positioned on a back surface of a semiconductor substrate through a first conductive adhesive layer and may be connected to an intercell connector between solar cells.
In a structure, in which metal wires are connected to a back surface of a solar cell, when a completed solar cell module is installed in a field and operates, the solar cell module may be affected by the seasons, the weather, or an installation position and exposed to an environment, in which a high temperature and a low temperature are continuously repeated.
In this instance, a temperature inside the solar cell module continuously repeats or reflects the high temperature and the low temperature. Hence, the metal wires may be thermally expanded or thermally contracted, and the metal wires and the electrodes of the solar cell may be disconnected from each other. Further, a physical adhesive strength between the metal wires and the intercell connector may be reduced, and the intercell connector may bend.
Further, when a plurality of conductive lines are connected to the intercell connector, the conductive lines are thermally expanded during a thermal process due to the thermal expansion of the metal wires. The intercell connector is deformed because of a shear stress of the conductive lines, and the conductive lines and the intercell connector are disconnected from each other.